Iburied my father in my heart.
now he grows in me, my strange son,
my little root who won’t drink milk,
little pale foot sunk in unheard-of night,
little clock spring newly wet
in the fire, little grape, parent to the future
wine, a son the fruit of his own son,
little father i ransom with my life.

source: lee, li-young. “little father.” book of my nights. rochester: boa editions, ltd., 2001. poetry foundation. web. 25 july 2011.

which structure is used in this excerpt from the poem “little father”?

haiku
free verse
iambic
ode